Thanks for the thoughtful responses @Opus 17 and @Carl ! The total refund here is above $22,000. I genuinely did not realize until 2020 that I had been overpaid. I brought up the overpayment issue on my own with the company after I realized this. I have emails to show that I brought it up with the company. They did send me a demand letter after my emails and advised that their confirmation email, combined with a copy of my cancelled check, should be enough to prove when repayment was received.
1. Do you think this is enough to establish unrestricted right should that become an issue? To clarify, the demand letter does not specifically say that I brought up the overpayment on my own.
2. Do you think I could/should request any documentation which can establish unrestricted right?
